In `ViewEncapsulation.Emulated` mode, the compiler must generate additional
combinations of selectors to handle the `:host-context()` pseudo-class function.
Previously, when there is was more than one `:host-context()` selector in a
rule, the compiler was generating invalid selectors.
This commit generates all possible combinations of selectors needed to
match the same elements as the native `:host-context()` selector.
Fixes#19199
PR Close#40494
ba3f99d7cc